slump

(noun) a noticeable deterioration in performance or quality. Synonyms: slack, drop-off, falloff, falling off. Examples: "The team went into a slump." "A gradual slack in output." "A drop-off in attendance." "A falloff in quality."

(noun) a long-term economic state characterized by unemployment and low prices and low levels of trade and investment. Synonyms: depression, economic crisis.

(verb) assume a drooping posture or carriage. Synonyms: slouch.

(verb) fall or sink heavily. Synonyms: slide down, sink. Examples: "He slumped onto the couch." "My spirits sank."

(verb) fall heavily or suddenly; decline markedly. Synonyms: fall off, sink. Examples: "The real estate market fell off."

(verb) go down in value. Synonyms: decline, correct. Examples: "The stock market corrected." "Prices slumped."